Matlock is a city in Sioux County, Iowa, United States.

[3] According to the United States Census Bureau, the city has a total area of 0.37 square miles (0.96 km2), all land.

There were 33 housing units at an average density of 87.3 per square mile (33.7/km2).

There were 35 housing units at an average density of 94.6 per square mile (36.5/km2).

17.6% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.

There were 35 housing units at an average density of 92.6 per square mile (35.8/km2).

18.2% of all households were made up of individuals, and 3.0% had someone living alone who was 65 years of age or older.

There were 4.0% of families and 11.1% of the population living below the poverty line, including 17.4% of under eighteens and none of those over 64.